Question

The accompanying data was read from a graph. The independent variable is SO₂ deposition rate (mg/m²/d) and the dependent variable is steel weight loss (g/m²).

x	13	18	33	43	45	114
y	270	350	460	500	560	1190

(a) Construct a scatter plot.

(b) Calculate the equation of the estimated regression line. (Round all numerical values to two decimal places.)
y =

(c) What percentage of observed variation in steel weight loss can be attributed to the model relationship in combination with variation in deposition rate? (Round your answer to one decimal place.)
%

(d) Because the largest x value in the sample greatly exceeds the others, this observation may have been very influential in determining the equation of the line. Delete this observation and recalculate the equation. (Round all numerical values to two decimal places.)
y* =

Answer 1

a)

b)

y^ =157.42+8.97x

c)

SST=Syy=		538,550.0000
SSE =Syy-(Sxy)2/Sxx=		2,989.123
SSR =(Sxy)2/Sxx =		535,560.8770

Coeffficient of determination R^2 =SSR/SST=

0.9944~ 99.4 %

d)

removing point (114,1190):

y^ =186.53+7.94x